Prognosis And Prognostic Factors Of Local Advanced Low Rectal Carcinoma In The Anterior-lateral Wall

Objective: The primary aim of this study was to explore the prognostic factors of patients with locally advanced low rectal carcinoma in the anterior-lateral wall by comparing the prognosis with the patients of low rectal carcinoma in the posterior wall,and providing a reference for therapy choice for locally advanced low rectal carcinoma in the anterior-lateral wall.Methods: Retrospective analysis of 333 patients of low rectal cancer without distant metastases who were treated in the Department of Colorectal Surgery in Fujian Medical University Union Hospital from January 2008 to December 2012,which was assigned into two subgroups(anterior-lateral wall,posterior wall) according to the 7th General Rules for Clinical and Pathological Studies on Cancer of the Colon,Rectum and Anus.Preoperative T staging was evaluated according to The Radiologic Society of North America(RSNA) proposal criteria. The differences between two subgroups(anteriorlateral wall, posterior wall) on the prognosis and prognostic factors were retrospectively compared.Results: For the patients with locally advanced low rectal cancer, the anterior-lateral wall group and posterior wall group revealed no significant differences in the 3-year disease-free survival rate(76.9% vs 83.1%,P=0.227),local recurrence rate(13.3% vs7.7%,P=0.151)and distant metastatic rate(12.5% vs 15.8%,P=0.174).Univariate analysis showed that circumferential resection margin involvement, lymphatic metastasis, lower differentiation of tumor, non anus preserving operation(P<0.05 for all, OR> 1.0 for all)were significant prognostic factors for DFS. Cox multivariate analysis indicated that circumferential resection margin( CRM) involvement,lymphatic metastasis, non anus preserving operation(P<0.05 for all) was independent prognostic factor for DFS. The patients between the two subgroups(anterior-lateral wall,posterior wall) who received neoadjuvant radiochemotherapy revealed no significant differences in metastasis rate of lymph nodes(30.3% vs 37.5%,P=0.340),the patients treated by surgery only between the two groups revealed no significant differences in metastasis rate of lymph nodes either.The rate of CRM involvement(6.9% vs 3.9%,P=0.683)had no significant differences between the clinical T3 stage anterior-lateral wall group and the clinical T3 stage posterior wall group after neoadjuvant radiochemotherapy.The same T stage patients treated by surgery only were significantly different in the rate of CRM involvement(14.3% vs 0.0%,P=0.022)between the two groups.Conclusions:For the patients with locally advanced low rectal carcinoma in the anterior-lateral wall, the rate of CRM involvement were significantly different from the patients with local advanced low rectal carcinoma in the posterior wall,while the rate reduced when T3 stage patients with low rectal cancer in the anter-ior-lateral wall received neoadjuvant radiochemotherapy. CRM involvement, lymphatic metastasis,non anus preserving operation were independent prognostic factors for patients with low rectal cancer in the anterior-lateral wall.